Figure - available from: APL Photonics
This content is subject to copyright. Terms and conditions apply.
Two scenarios of mirror coupling: (a) Schematic of the cross-sectional image of vertical optical coupling using the turning mirror of the flip-chip bonded silicon photonic chip. Reprinted with permission from Noriki et al., J. Lightwave Technol. 34, 3012 (2016). Copyright 2016 IEEE. (b) Side view schematic of vertical coupling using the turning mirror and grating coupler of a 3D integrated hybrid laser, reprinted with permission from Song et al., Opt. Express 24, 10435 (2016). Copyright 2016 The Optical Society.
Source publication
Increasing demand for every faster information throughput is driving the emergence of integrated photonic technology. The traditional silicon platform used for integrated electronics cannot provide all of the functionality required for fully integrated photonic circuits, and thus, the last decade has seen a strong increase in research and developme...
Similar publications
Microfluidics-enhanced bioprinting holds great promise in the field of biofabrication as it enables the fabrication of complex constructs with high shape fidelity and utilization of a broad range of bioinks with varying viscosities. Microfluidic systems contain channels on the micrometer-scale, causing a change in fluid behaviors, enabling unconven...
Citations
... Moreover, flip-chip bonding is more susceptible to temperature variations, requiring more consideration of the thermal expansion coefficient of thermal expansion between the chip and the substrate. These factors pose challenges for high-speed and low-cost applications [37,38]. ...
The quantum random number generator (QRNG) operates based on fundamental quantum mechanical principles to produce high-quality random numbers. Recently, chip-based QRNGs have garnered significant attention due to their compact size, low cost, and reduced power consumption. In this work, we demonstrate a hybrid integrated QRNG leveraging continuous-wave (CW) laser phase fluctuations. Using advanced hybrid packaging techniques, we integrate a tunable, unbalanced Mach–Zehnder interferometer (uMZI), laser, and InGaAs photodiode (PD) within a 14-pin butterfly package. To enhance the long-term stability and reliability of the QRNG, a negative temperature coefficient (NTC) thermistor is also attached to the chip for thermal regulation. The resulting integrated QRNG has a footprint of just 30 mm × 12.7 mm, and delivers a random number generation rate of 4.68 Gbps after min-entropy evaluation and post-processing. The combination of compact size and high-speed performance makes this hybrid integrated QRNG ideal for high-speed, large-scale applications.
... In the monolithic integration technique, the devices are made of the same material that hosts the quantum emitters [26]; however, the devices are limited by performance issues induced by the intrinsic material properties. For example, the device can perform below the optimum level due to low electrical conductivity and optical gain [22,27]. On the other hand, in the heterogeneous technique wafer bonding is required to bond different materials. ...
Single photon emitters in hexagonal boron nitride are based on fluorescent point-like defects. These defects typically have exceptional photophysical properties and therefore been the focus of extensive research due to their potential to advance photonic quantum technologies. However, achieving scalable integration of these emitters to arbitrary platforms with high yield while retaining their characteristics remains a significant challenge, particularly when the target substrate is not compatible with the fabrication method. In this work, we introduce an all-dry transfer method aimed at addressing these challenges with improved effectiveness compared to existing techniques. This polymer stamp-assisted transfer method maintains high output and preserves the fundamental characteristics of the emitters while eliminating wet chemical processes. A comprehensive post-transfer characterization verified not only the maintenance of the defining characteristic of a single photon emitter, the second-order correlation function , but also showed improvement by about 46%. In contrast, the lifetime, emission spectrum, and the photostability showed only negligible change, demonstrating that the characteristics of the emitters were retained during the transfer process. This transfer technique has success rate of 81.8%, determined by the proportion of single photon emitters that retain their optical and preserve physical structure post-transfer. This high success rate shows the potential to scale the integration of single photon emitters across diverse platforms. We expect that this process contributes to the applications of boron nitride defects in quantum technologies.
... Monolithic integration uses a single material, such as silicon or III-V semiconductors, to fabricate all components together, enabling high-density integration and efficient production, though material incompatibility can be a challenge [111]. Heterogeneous integration, on the other hand, combines different materials for specific functions, like using III-V materials for active components and silicon for passive ones, offering greater flexibility but introducing complexities in bonding and alignment [112]. Hybrid integration is a variation that combines photonic components sourced from different platforms, allowing for specialized functionality but often at a higher cost. ...
... In this approach, passive and active components are manufactured separately-often in different production lines-before being combined. While effective, this method significantly increases the complexity of fabrication, reduces scalability, and raises production costs [112,252]. Its key advantage is the elimination of the need for active alignment during assembly [252]. Another challenge in developing miniaturized systems for MIR photonics is the requirement for specialized, efficient power supplies and control electronics to operate compact QCL lasers effectively. ...
Mid-infrared (MIR) photonic sensors are revolutionizing optical sensing by enabling precise chemical and biological detection through the interrogation of molecules' unique vibrational modes. This review explores the core principles of MIR photonics, emphasizing the light-matter interactions within the 2-20 µm wavelength range. Additionally, it examines innovative sensor architectures, such as integrated photonic platforms and optical fibers, that enhance sensitivity, specificity, and device miniaturization. The discussion extends to groundbreaking applications in environmental monitoring, medical diagnostics, industrial processes, and security, highlighting the transformative impact of these technologies. This comprehensive overview aims to illuminate the current state-of-the-art while inspiring future developments in MIR photonic sensing.
... The waveguide isolator concept demonstrated in this work allows direct hybrid integration with other optoelectronic elements on a common silicon photonic platform using the same type of etched pockets, drop-in alignment and die bond attachment methods currently used for hybrid integrating III-V sources or photodetectors 66 . In our work so far, the laser-written waveguides were designed to match standard SMF fibres and are therefore expected to couple efficiently to standard silicon photonic fibre edge coupling elements. ...
Optical isolation based on a non-reciprocal effect is crucial for proper operation of several high-performance photonic devices such as in telecommunications, light detection and ranging, and even quantum platforms. The magneto-optical Faraday rotation is the most commonly used non-reciprocal effect as it offers unique advantages, including broadband operation, wide input optical power range, low insertion losses and high optical isolation, but it is currently not conducive to miniaturization. Two major impediments hinder the direct integration of Faraday isolators into photonic chips: the need for bulky external magnets and the challenging fabrication of low-loss waveguides that would eliminate the need for free-space coupling optics. Here we have addressed both challenges using a new femtosecond laser writing technique to create waveguides within the bulk of latched bismuth-doped iron garnet slabs without altering its magneto-optic functionality. As a result, we have achieved a Faraday rotator waveguide exhibiting <0.15 dB insertion loss with a figure of merit of 346° dB⁻¹. By interposing this Faraday rotator between two 30-μm-thick polarizers, we further demonstrate a miniaturized optical isolator waveguide with >25 dB isolation ratio and <1.5 dB insertion loss over the entire optical telecom C-band for hybrid integration to photonic circuits without lenses and external magnet.
... While this discrepancy is partly explained by the greater maturity of external laser fabrication processes, heterogeneous lasers must contend with inherent, nontrivial disadvantages. For instance, the passive layer of a typical heterogeneous platform places a thermal barrier between the laser and its heat sink [14], which can limit output power as compared to cooler monolithic devices. For nonlinear applications in particular, overcoming this limitation is essential. ...
Heterogeneous integration of GaAs-based lasers with frequency doubling waveguides presents a clear path to scalable coherent sources in the so-called green gap, yet frequency doubling systems have so far relied on separately manufactured lasers to deliver enough power for second harmonic generation. In this work, we propose a photonic integrated circuit (PIC) which alleviates the performance requirements for integrated frequency doublers. Two gain sections are connected by waveguides, with a frequency converter and a wavelength separator in between. The fundamental light circulates between the gain sections until it is converted and emitted through the wavelength separator. Variants of this separated gain PIC are discussed, and the PIC is implemented with thin film lithium niobate and directly bonded GaAs-based lasers, coupled by on-chip facets and adiabatic tapers, realizing visible light generation in the 515-595 nm range.
... Because of this last advantage, optical power losses are moderate at the interface between waveguides, although implemented using heterogeneous technologies. An interesting description of the experimental methods used to perform both hybrid and heterogeneous integration in optical devices can be found in [85]. Heterogeneous integration approaches have been adopted in fabricating integrated optical spectrometers [86][87][88]. ...
On-chip spectrometers are increasingly becoming tools that might help in everyday life needs. The possibility offered by several available integration technologies and materials to be used to miniaturize spectrometers has led to a plethora of very different devices, that in principle can be compared according to their metrics. Having access to a reference database can help in selecting the best-performing on-chip spectrometers and being up to date in terms of standards and developments. In this paper, an overview of the most relevant publications available in the literature on miniaturized spectrometers is reported and a database is provided as an open-source project to which researchers can have access and participate in order to improve the share of knowledge in the interested scientific community.
... A multi-layer heterogeneous structure is a promising platform for envisioned photonic integrated circuits (PICs) [1]. Benefiting from the advanced heterogeneous integration and canonical planar microfabrication technique, a myriad of applications including LIDAR [2,3], photonic computing [4,5], and optical communications [6] are emerging by virtue of low power consumption, high speed, and device compactness of PICs. ...
Lithium tantalate on insulator (LTOI), taking advantage of high cost-effectiveness, ultra-low optical loss, and prominent electro-optic (EO) coefficient, shows great potential as an integrated waveguide-based optical platform for commercialization. Further research on monolithic nonlinear source generators with tunable features is crucial in its early stages. Here, we fabricate low-loss microring resonators (intrinsic Q value above 4 × 10⁶) via universal subtractive manufacturing. Both Kerr and EO combs are realized based on X-cut LTOI high-Q resonators. Specifically, we elucidate the complicated synergy caused by a photorefractive (PR) effect and thermo-optic modulation, observing the soliton step using the facile laser scanning technique. Furthermore, the preliminary experimental result of the static EO comb is also exploited in a 20 GHz free spectral range (FSR) LTOI microring resonator, verifying the versatility of this unique photonic platform for on-chip microcomb generation.
... PICs are built on a variety of material platforms, each offering unique advantages and challenges. A single platform cannot cover all possible applications [6]. For example, the Silicon-on-Insulator (SOI) platform [7] has emerged as a mature and commercially viable technology for PICs due to its high refractive index contrast and compatibility with existing complementary metal oxide semiconductor (CMOS) manufacturing processes. ...
In this paper, we present our process design kits (PDKs) component performances for different wavelengths in the visible to near-infrared (VIS-NIR) range on Shanghai Industrial μTechnology Research Institute's (SITRI's) 200 mm silicon nitride (SiN) photonics platform. SiN waveguide platform has emerged as a promising technology due to its low optical loss, relatively high refractive index, and transparency across the VIS-NIR spectrum. The industrialization of SiN platforms requires matured PDKs. On SITRI's 200 mm SiN photonics platform, we developed PDKs using both Plasma-Enhanced Chemical Vapor Deposition (PECVD) and Low-Pressure Chemical Vapor Deposition (LPCVD) processes, with SiN layers of 180 nm and 150 nm thicknesses, respectively. The fabricated waveguides exhibit low propagation loss, ranging from 2.5 dB/cm to 0.34 dB/cm from 532 nm to 860 nm. Additionally, we present a low bending loss which is less than 0.06 dB/90° with a radius of 100 μm. Furthermore, the loss of the linear grating coupler (LGC) is less than 2.6 dB at 785 nm. We have also achieved low-loss splitters, including 1×2 multimode interference (MMI) coupler, and directional coupler (DC), with a minimum excess loss of 0.03 dB. Additionally, micro ring resonator with high quality (Q) factors of 146,000 has been demonstrated. Our work on developing these PDKs will open new opportunities for researchers and developers to design and fabricate advanced photonic devices on the SiN platform in SITRI's 200 mm fabrication line.
... Different materials such as silicon nitride (SiN) [46,47], silicon (Si) [48][49][50], lithium niobate (LN) [51][52][53], gallium arsenide (GaAs) [54,55], indium phosphide (InP) [55][56][57], and silicon carbide (SiC) [15,16,[58][59][60][61][62][63][64][65][66] have been used to demonstrate various on-chip photonic applications including switching, filtering, splitting, combining, amplification, modulation and many more. However, no single material meets all the requirements of an efficient and high-throughput photonic integrated circuit [67,68]. For example, SiN waveguide deposited by low pressure chemical vapor deposition (LPCVD) with specific design parameters (thickness 40 nm and width 2 um) provides ultra-low losses of down to 0.1 dB m −1 (figure 3(a)) [32,69]. ...
Recent efforts in quantum photonics emphasize on-chip generation, manipulation, and detection of single photons for quantum computing and quantum communication. In quantum photonic chips, single photons are often generated using parametric down-conversion and quantum dots. Quantum dots are particularly attractive due to their on-demand generation of high-purity single photons. Different photonic platforms are used to manipulate the states of the photons. Nevertheless, no single platform satisfies all the requirements of quantum photonics, as each platform has its merits and shortcomings. For example, the thin-film silicon nitride (SiN) platform provides ultra-low loss on the order of 0.1 dB m⁻¹, but is incompatible with dense integration , requiring large bending radii. On the other hand, silicon on insulator offers a high refractive index contrast for dense integration but has a high absorption coefficient at the emission wavelengths (800–970 nm) of state-of-the-art QDs. Amorphous silicon carbide (a-SiC) has emerged as an alternative with a high refractive index (higher than SiN), an extended transparency window compared to Silicon, and a thermo-optic coefficient three times higher than that of SiN, which is crucial for tuning photonic devices on a chip. With the vision of realizing a quantum photonic integrated circuit, we explore the hybrid integration of SiN/a-SiC photonic platform with quantum dots and superconducting nanowire single-photon detectors. We validate our hybrid platform using a brief literature study, proof-of-principle experiments, and complementary simulations. As a proof-of-principle, we show a quantum dot embedded in nanowires (for deterministic micro-transfer and better integration) that emits single photons at 885 nm with a purity of 0.011 and a lifetime of 0.98 ns. Furthermore, we design and simulate an adiabatic coupler between two photonic platforms, a-SiC and SiN, by aiming to use the benefits of both platforms, i.e. dense integration and low losses, respectively. Our design couples the light from SiN waveguide to a-SiC waveguide with 96% efficiency at 885 nm wavelength. Our hybrid platform can be used to demonstrate on-chip quantum experiments such as Hong–Ou–Mandel, where we can design a large optical delay line in SiN and an interference circuit in a-SiC.
... In recent years, the production of thin-film platforms with second-order nonlinear coefficients ( (2) ), such as lithium niobate, aluminium nitride, indium phosphide, have boosted research on integrated nonlinear photonic devices, featuring scalability, reliability, and low power consumption [5]- [8]. However, integrating these emerging nonlinear platforms with CMOS-compatible platforms remains challenging, hindering the fabrication of large-scale photonic circuits with (2) effects [9], [10]. ...
Two-dimensional (2D) layered materials without centrosymmetry, such as GaSe, have emerged as promising novel optical materials due to large second-order nonlinear susceptibilities. However, their nonlinear responses are severely limited by the short interaction between the 2D materials and light, which should be improved by coupling them with photonic structures with strong field confinement. Here, we theoretically design photonic crystal circular Bragg gratings (CBG) based on hole gratings with a quality factor as high as Q = 8 × 10³, a mode volume as small as V = 1.18 (λ/n)³, and vertical emission of light field in silicon nitride thin film platform. Experimentally, we achieved a Q value up to nearly 4 × 10³, resulting in a 1,200-fold enhancement of second harmonic generation from GaSe flakes with a thickness of 50 nm coupling to the CBG structures under continuous-wave excitation. Our work endows silicon-based photonic platforms with significant second-order nonlinear effect, which is potentially applied in on-chip quantum light sources and nonlinear frequency conversion.
